1. Field of the Invention
The present invention relates to a device for drawing an elliptical curve having desired minor and major axes along given central axes.
2. Description of the Prior Art
Ellipse templates are widely used to draw ellipses in the technical drawing practice. Such an ellipse template has a plurality of elliptical holes defined in a plastic plate. There are known various devices for drawing elliptical patterns having minor and major axes which cannot be drawn using existing ellipse templates.
An ellipse template allows the central axes of an ellipse to be easily aligned with two orthogonal axes which are preset in a drawing, but is unable to draw an ellipse having desired minor and major axes along given central axes. The conventional ellipse drawing devices are complex in structure, and cannot easily bring themselves into alignment with the central axes of an ellipse. Though the existing ellipse drawing devices are large in size, the elliptical curves which can be drawn by these ellipse drawing devices are limited to certain sizes.
The major problems with the earlier ellipse drawing devices are that a number of manual steps are required to position the central axes of an ellipse into alignment with desired minor and major axes, and hence the ellipse drawing devices cannot easily be handled, and also that the drawing pressure with which an elliptical pattern is drawn on a sheet is not sufficient. In order to obtain a necessary drawing pressure, a special attachment has to be added to the ellipse drawing device, which is rendered more complicated.